The European Physical Journal Applied Physics

Research Article

Experimental study of the transmission of breakdown plasma generated during laser shock processing

L. Berthea1, R. Fabbroa1, P. Peyrea1 and E. Bartnickia1

Centre Laser Franco-Allemand (CLFA), Laboratoire pour l'Application des Lasers de Puissance (LALP), 16 bis, avenue Prieur de la Côte d'Or, 94114 Arcueil Cedex, France

Abstract

Shock wave generation from laser-produced plasma in water confinement regime for an incident 25–30 ns / 40 J / λ = 1.064 µm laser beam has been studied. Transmitivity measurement of the parasitic plasma breakdown at the surface of water confinement has been performed with a continuous laser probe. Above 6 GW/cm2 incident laser intensity, the critical electronic density for the laser wavelength is achieved inside the plasma by cascade ionization during the pulse duration. Above 10 GW/cm2, peak power density transmitted through the plasma saturates. The laser pulse transmitted through the breakdown plasma corresponds to the part of incident laser pulse preceding the transmission cut-off.

(Received January 6 1998)

(Revised April 16 1998)

(Accepted April 30 1998)

(Online publication August 15 1998)

PACS:

  • 52.50.Jm – Plasma production and heating by laser beams;
  • 62.50.+p – High-pressure and shock-wave effects in solids and liquids
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